| The results and perspectives of using marine transient electric field method (matem) on Arctic offshore |
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LEGEYDO P.Yu., LISITSYN E.DA MOISEEV YU. F., RAYKOVITCH A.I., KOVALENKO V.S. "Siberian Geophysical Scientific-Production Company" JSC, Russia, "Sevmorgeo" SC, Russia, During the last few years in practice of "Gazprom" geological works the electrical investigations MaTEM have been used successfully.
As well as in on shore investigations, in marine ones the straight and relaxation signals and, also, their spatial and temporal derivatives are being measured.But in this case, all measurements are made when the vessel moves at speed 4-5 nocks. The special generator and receiving floating lines, on board and technological equipment were invented for the works in motion. The special pre-processing allows to decrease considerably the influence of drifts of electrodes, signals, induced dew to light receiving line movement, and, also, telluric noise. Inversion based on "Cole-Cole" model lets us to determine anomalies of resistivity and chargeability that are connected with HC deposit existence. On the field data interpretation the seismic and lodging information is used. Since 2002 on geological work sectors in Ob and Taz bays that belong to the "JamburgGazdobycha" were done more then 4000 km of electrical profiles. Under experience, MaTEM investigations may be successfully used on parts preparing for drilling, as well as like primary method. To authors opinion, the usage of Ma ТЕМ in combination with seismic works can considerably increase the efficiency of geological investigations, especially in Barents and Kara seas with their high HC potential. |